Known lighting controls include an on/off mechanism having a button that actuates a momentary tactile switch when the button is pressed by a user. The on/off button of the Vareo® lighting control by Lutron Electronics Co., Inc. of Coopersburg, Pa. is located next to a slide actuator of a dimmer mechanism. Referring to FIGS. 1 and 2, the prior on/off button 10 of the Vareo® lighting control is shown separately from the lighting control along with flexible button supports 12 located at opposite ends of the button 10. The button supports 12 are integrally molded with the button 10 from a thermoplastic material such as polycarbonate.
Each of the button supports 12 includes a tab 14 connected to one of the ends of button 10 and a pair of elongated legs 16 extending from opposite sides of the tab 14. A pad 18 projects downwardly (with respect to the view of FIG. 1) from each of the legs 16 for contact with an underlying support surface of the lighting control. Referring to FIG. 2, the pads 18 on the left extend further from the associated legs 16 than those on the right to provide for contact with different support surfaces (e.g., surfaces of a yoke and an adapter).
Referring to the rear perspective view of FIG. 2, a pair of retainer prongs 20 extend from a rear surface of the button 10 for snap attachment with the lighting control to limit unintended removal of the button 10. Posts 22 extend from the rear surface of button 10 for contact with a pivoting hinge bar (not shown) of the lighting control. The hinge bar of the lighting control is adapted to contact the switch of the on/off mechanism to transfer actuating motions of the button 10 to the switch.
Each pair of legs 16 is adapted to flex in response to load applied to the button 10 to provide for a variety of button motions. Contact near the center of the button 10 results in substantially equal flexing of all of the legs 16 and uniform deflection of the button 10. Contact adjacent one of the ends of the button 10 flexes the legs 16 adjacent that end causing the end to deflect while deflection of the opposite end of button 10 is minimal. Contact adjacent one of the opposite sides of the button 10 results in deflection of that side of the button 10 with respect to the opposite side.
The use of polycarbonate provides for integral molding of the button 10, button supports 12, retainer prongs 20 and posts 22 from the same material. In addition to providing for integral molding, polycarbonate provides hardness characteristics desired for actuator buttons. The integral construction of the button supports 12 from the same material as the button 10, although facilitating fabrication, results in less than ideal operating conditions for the flexing button supports 12. As described above, the legs 16 of the button supports 12 contact the yoke of the lighting control. Heat is transferred to the legs 16 of the button support 12 from the yoke during operation of the lighting control. Such heating of the polycarbonate and repeated flexing of the legs 16 can lead to fatigue failures at the junctions between the legs 16 and the tabs 14.